Veneer bend



Nov. 28, 1939. E. E. ALEXANDER 2,181,164

VENEER BEND Filed Feb. 20, 1939 [010 if JAE-N055 Patented Nov. 28, 1939UNITED STATES PATENT OFFICE 5 Claims.

This application is a continuation in part of my United Statesapplication Serial Number 202,651, filed April 18, 1938.

This invention relates to the formation of bends in wood andparticularly in built-up or ply wood of that nature having a core overwhich one or more plies of veneer are secured.

The primary purpose of this invention is to provide a structurepermitting the formation of a bend in such material which will give aperfectly smooth and continuously curved exterior surface and at thesame time may be formed without the necessity of having to insert sticksor the like to'complete the inner portion of the bend.

A further object of the invention is to provide an exceedingly simpleand relatively cheap means for relieving the backside of that zone whichis to be bent in a manner which will permit the formation of a smoothinterior surface around the bend. a

These and many other objects and advantages will become apparent tothose versed in the art in the following description of the invention asillustrated in the accompanying drawing, in which Fig. 1 is an insideelevation of a length of a panel in flat form;

Fig. 2, an edge view of the panel;

Fig. 3, a similar edge view but showing the panel in the bent position;

Fig. 4, an outside elevation of the bend;

Fig. 5, an edge view of a panel in slightly modifled form; and

Fig. 6, an edge view of the panel as indicated in Fig. 2 in adisassembled relation.

Like characters of reference indicate like parts throughout the severalviews in the drawing.

A panel is formed in the usual manner to have a body or core I!) on theoutside of which is glued one or more plies of veneer wood I I, hereinshown as two in number. The inside of the panel is preferably providedwith one or more plies of veneer glued to the core Ill, these pliesbeing designated by the numeral I2 and shown as being two in number. Thepanel is formed fiat and the core I0 is cut away from the backside and aply of veneer I3 is glued directly against the outer plies II. On top ofthis added ply I3 is placed a second ply of veneer I4.- The ends only ofthis second ply I4 are glued to the ply I3. Then on top of the ply I4 isplaced a block I5 to fill out the balance of the thickness of the coreI0 and this block is glued over its entire underside to the ply II. Overthe block I5, and preferably extending somewhat therebeyond, are placedone or more plies of veneer I6 to complete the building up of this bendzone to the thickness of the balance of the panel.

The outer plies I6 have their grain turned to be transversely directedacross the panel rather than longitudinally thereof. Then a number ofspaced apart cuts H in the nature of slots are made through the plies I6and through-the block I5 down to the ply of veneer I4. The shape ofthese cuts I1 may vary, but, in the form shown, are narrow V-slots ofsuch width and in such number that when the bend is made these slotswill be completely closed and glue placed therein to cause one side ofeach slot to be held in close intimate contact with the other side. Afurther out I8 is made at one end of the block I5 by cutting entirelythrough the plies IS, the block I5, and the ply I4. This cut is madesufliciently wide, as indicated in Fig. 2, as will permit the rolling upof the block I5 as indicated by the dash lines, it being remembered thatthis top ply I4 is not glued to the under my I3 throughout its majorlength.

The panel is then bent to give the desired curve, here shown as a ninetydegree curve, Fig. 3, whereupon .the block I5 will be carried around, asindicated, to close the slots therein and to cause the end cut to becompletely closed by relative longitudinal travel between the block I5and its veneer ply I3 over the veneer ply I4 and the outer veneer pliesII. This end cut,'as indicated, must be so proportioned that this travelwill cause the end of the block I5 to come into abutment with theopposing stationary end that is securely glued in position. Prior tobending, the central block I5 is lifted as indicated by the dash lines,and a film of glue is placed thereunder. Also glue is placed in thevarious slots and across the faces of the end cut. Following the bendingof the panel, the bend is held in any suitable manner until this gluesets or dries so that the bend will become permanent through the holdingaction of the glue.

It is to be noted that the veneer ply I4 which is glued to the block I5securely ties together the individual blocks formed by the slots I'I.Alsoit is to be noted that by placing the inner plies of veneer It tohave their grain extend transversely across the panel, the veneerremaining on the inside surfaces of the individual blocks between theslots will not tend to chip oil? while these slots are being cut norwill they tend to separate there after.

As a modified form, it is possible, as indicated in Fig. 5, to formthecore I5 without gluing its back to the under veneer I4, the initiallyloose ply. It being omitted in this form, and two plies I3 being usedand glued to the outer plies II. In this case, the block 15 is not cutentirely therethrough by the slots I! so that the uncut portion willserve as means to tie together the portions of the block between cuts,

In any event, the veneer plies l3 and I4 are preferably made out ofrelatively soft wood so that when the bend is formed, the portions ofthe block l5 along the fold lines back of the slots'll may embedthemselves in these plies of soft wood instead of carrying those linesout in visible form through the outer plies ll. Of course, the closerthe slots H are placed, the less width there is between the slots aroundthe bend adjacent the plies l3 and hence the less tendency there is forlines of folding of the block to show" through the outer veneer plieswhen the bend is completed.

While I have herein shown my invention in the best form as now known tome, it is entirely obvious that structural changes may be made withoutdeparting from the spirit of the invention and I, therefore, do notdesire to be limited to that precise form beyond the limitations as maybe imposed by the following claims.

I claim:

1. For a ply wood bend, a panel having a core, an outer veneer plyadhering thereto, an added ply of veneer behind said outer ply extendingat least over the zone of the bend, said core being provided with aplurality of relatively closely spaced slots extending transverselyacross the panel back of said added ply, that part of the core which isout being free to travel longitudinally of the panel relative to saidouter ply and having an end portion removed equal to said travel.

2. For a ply wood bend, a panel having a core,

an outer veneer ply adhering thereto, an added ply of veneer behind saidouter ply extending at least over the zone of the bend, said core beingprovided with aplurality of relatively closely spaced slotsextendingtransversely across the panel back of said added ply, that part of thecore which is cut being free to travel longitudinally of the panelrelative to said outer ply and having'an end portion removed equal tosaid,

travel, said added ply being sufficiently soft to permit embeddingtherein of bends of said out portion of the core occurring under saidslots.

3. For a ply wood bend, a panel having a core, an outer veneer plyadhering thereto, a second ply of veneer behind said outer ply extendingat least over the zone of the bend, 'said core being provided with aplurality of relatively closely spaced slots extending transverselyacross the ipanel back of said second ply, that part of the \core whichis out being free to travel longitudinally of the panel relative to saidouter ply and having an end portion removed equal to said travel, saidslotted core portion having its back glued to said second veneer ply,and said second ply being anchored at one end and free to shift over theouter ply with said core portion.

4. For a ply wood bend, a panel having a core, an outer veneer plyadhering thereto, a second ply of veneer behind said outer ply extendingat least over the zone of the bend, said core being provided with aplurality of relatively closely spaced slots extending transverselyacross the panel back of said second ply, that part of the core which isout being free to travel longitudinally of the panel relative to saidouter ply and having an end portion removed equal to said travel, saidslotted core portion having its back glued to said second veneer ply,and said second ply being anchored at one end and free to shift over theouter ply with said core portion, said slots extending entirely throughsaid core portion to said second ply.

5. For a ply wood bend, a panel having a core, an outer veneer plyadhering thereto, a second ply of veneer behind said outer ply extendingat least over the zone of the bend, said core being provided with aplurality of relatively closely spaced slots extending transverselyacross the panel back of said second ply, that part of the core which isout being free to travel longitudinally of the panel relative to saidouter ply and having an end portion removed equal to said travel, saidslottedcore portion having its back glued to said second veneer ply, andsaid second ply being anchored at one end and free to shift over theouter ply with said core portion, said slots extending entirely throughsaid core portion to said second ply, that part of the corecarrying saidslots consisting of a separate filler block.

ELMO E. ALEXANDER.

